Materials: Cheaper and more sustainable production of propylene oxide

A more sustainable and economical method to directly produce propylene oxide — a material commonly used in various consumer products, such as paint, shoes and cosmetics — using propane and oxygen, is described in a Nature Communications paper. The findings may assist in moving toward more environmentally friendly production approaches in some consumer goods markets.

Propylene oxide is an important starting material for the industrial production of polyurethane and propylene glycol polymers; materials used in a wide variety of consumer goods, including paints and coatings, adhesives, furniture cushions, shoes, and cosmetics. However, this critical material is currently produced through a series of expensive and environmentally unfriendly steps.

Annette Trunschke and colleagues reported that propylene oxide can be synthesized directly from mixtures of propane and oxygen by optimizing reaction conditions like temperature or gas mixture composition rather than engineering the catalyst alone. They found that the approach could be applied to a wide variety of inexpensive catalyst materials, such as quartz wool and silica, and yielded mixtures of propylene and propylene oxide with limited CO2 emission compared to current industrial production methods. CO2, a common product of propane over-oxidation, also raises the production cost of propylene oxide and is a greenhouse gas. As revealed in the study, the key principle to synthesizing propylene oxide was not the catalyst structure, but instead a proper mixture of starting materials that interact minimally with the catalyst, thus avoiding additional and unwanted chemical side reactions.

The authors also conducted a preliminary economic analysis of the technology and found that the approach is scalable and, depending on the price of raw materials, certainly competitive against current industrial technologies. Moreover, the described methodology has the added benefits of potentially reducing costs for consumer goods production and creating more sustainable manufacturing routes.